1. Field of the Invention
The present invention relates to a semiconductor device including a transistor including an oxide semiconductor film. Furthermore, the present invention relates to a display device including the semiconductor device.
2. Description of the Related Art
Attention has been focused on a technique for forming a transistor using a semiconductor thin film formed over a substrate (also referred to as a thin film transistor (TFT)). Such a transistor is used in a wide range of electronic devices such as an integrated circuit (IC) or an image display device (display device). A silicon-based semiconductor material is widely known as a material for a semiconductor thin film applicable to a transistor. As another material, an oxide semiconductor has attracted attention.
For example, a transistor including an oxide semiconductor containing indium (In), gallium (Ga), and zinc (Zn) as an active layer of the transistor has been disclosed (see Patent Document 1 and Patent Document 2).
In recent years, with increased performance and reductions in the size and weight of electronic appliances, demand for a display device in which a driver circuit is formed so that miniaturized transistors, connection wirings, or the like are integrated with high density, and the driver circuit and the display device are provided on the same substrate has risen.